HVAC and ERV Installed

The HVAC and ERV (energy recovery ventilator) have been roughed in/installed. The HVAC system and ERV was installed by McNutt Service Group and boy did they do a great job of sealing all the duct work. Mastic was used in great quantities and this should go a long way to achieving an excellent duct blaster test score. All the ducts in this prototype home were designed to be in the conditioned space or thermal building envelope. My goal from the beginning was to build a home that was orientated properly, very well insulated, and with an HVAC system that was designed and sized specifically for this home. With great southern exposure, Eco-Panels for the walls and spray foam for the roof and subfloor, I had achieved the first two goals. Every home should have the HVAC installer/company perform a Manual J (load calculation for heating and cooling sizing) that is verified by the Energy Star (HERS) rater prior to installation. After much contemplation, I decided to go with a high performance air to air heat pump for heating and cooling the home. At first I thought about installing a ground source geothermal system, but because I am attempting to build this home for less than $95 per square foot, many buyers in the affordable housing category may not be able to take advantage of these tax credits or afford the initial up front costs of a geothermal system. I have been asked by several people why I did not at least install a gas back up furnace for potentially better heating performance. My answer is simple--this home is being roughed in for future solar (photovoltaic) panels that will ultimately power the home. In my opinion there is plenty of evidence out there highlighting the fact that we need to significantly reduce our dependence on fossil fuels. If the heat pump and passive solar design are for some reason not able to heat the home effectively, I have designed it so I can add a wood stove or pellet stove in the future. The ERV was included because my goal is to build an extremely tight home. "Build it tight and ventilate it right" is a popular saying in the green building industry. The ERV provides continuous ventilation for the entire house, exausting stale indoor air and replacing it with fresh air from the outside. The ERV is rated to recapture about 75-80% of the conditioned air before it leaves the home. This means that in the winter when you are spending money to heat the home and bringing in cold fresh air--75-80% of that heat is recaptured or not lost. ERVs can also be fitted with different filtration systems depending on the homeowners needs for indoor air quality.